1. Field of the Invention
The present invention relates to a pressure reducing valve, which includes a piston that is displaceable depending on a pressure in a decompression chamber.
2. Description of the Related Art
As well known in the art, pressure reducing valves function to reduce the pressure of a high-pressure fluid to a given pressure. The present applicant has proposed a diaphragm-type pressure reducing valve, as disclosed in Japanese Laid-Open Patent Publication No. 2005-227860.
The diaphragm-type pressure reducing valve disclosed in Japanese Laid-Open Patent Publication No. 2005-227860 includes a valve rod and a valve element member that is fitted over the valve rod. The pressure reducing valve is closed or opened when the valve element member is seated on or is spaced away from a valve seat.
When a high-pressure fluid flows in between the valve rod and the valve element member, the valve element member may be lifted off the valve seat or become deformed due to the fluid that presses outwardly from the inside. To avoid this problem, a seal member such as an o-ring is interposed between the valve rod and the valve element member, so as to provide a seal between the valve rod and the valve element member.